Coiling means for concavo-convex springs



Aug. 25, 1931. H. A. FARRAND 1,820,789

COILING MEANS FOR CONCAVO-CONVEX SPRINGS Filed Jan. 21. 1927 I III/1111114.! I!!! Patented Aug. 25, 1931 UNITED STATES PATENT OFFICE HIRAIM A. FARRAND, OF BERLIN, NEW HAMPSHIRE, ASSIGNOR'TO HIRAM A. FARRAND,; IN 0., OF BERLIN, NEW HAMPSHIRE, A CORPORATION OF NEW HAMPSHIRE COILING MEANS FOR CON CAVO-CONVEX SPRINGS Application filed January 21, 1927. Serial No. 162,512.

My invention relates to springs having an arcuate cross-sectional form and which are known as concavo-convex springs. Such springs are adapted to many uses and are particularly adaptable for use as the foundation for resilient rules, such as that shown and described in my co-pending application, Serial Number 143,267, filed October 21, 1926. Such a spring when in an unrestricted state will extend itself longitudinally into a rod-like form, due to its arcuate cross-section. In order to utilize such a spring as a rule which can be conveniently carried, it is necessary to reduce the spring to a compact form. Devices for effecting such a reduction are shown in my U. S. Patent No. 1,402,589, dated January 3, 1922, and in my two co-pending applications, Serial Number 155,268, filed December 16, 1926, now Patent N0.'1,730,199 and Serial No. 159,189, filed January 5, 1927. Each of the above devices shows means for reducing the spring to a spirally wound coil.

My present invention comprises means for reducing a concave-convex spring into a form having curved sections alternating with straight sections. The spring when in such form consists of a series of layers wound either externally one upon the other or internally one within the other. Thestructural details and the operation of the device will be fully disclosed hereinafter, reference being had to the accompanying drawings, of which:

Fig. 1 is a side elevation of a device designed to reduce the spring rule into an internally wound compact form;

Fig. 2 is a sectional plan view taken on the line 2-2 of Fig. 1;

Fig. 3 is a view of the spring rule completely wound;

Figs. 4 and 5 are opposite side elevations of a device designed to reduce the spring rule into an externally wound compact form;

Fig. 6 is an end elevation of the structure illustrated in Figs. 4 and 5;

Fig. 7- is a sectional elevation taken on the line 77 of Fig. 5;

Fig. 8 is a cross-sectional view of the spring when unrestricted; and

Fig. 9 shows a triangular formation of the compact form of the spring.

Referring to Figs. 1 and 2 of the drawings, 1 illustrates a frame comprising a longitudinal bar 2 having end portions 3 extending at right angles to the plane of the bar 2 and thereafter turned inward as at 4, 4 toward each other in a plane parallel to the bar 2. Between the inturncd ears 4, 4 and the bar 2 is rotatably mounted a pair of rollers 5, 5, each being journaled on a sleeve 6 extending between the adjacent inner faces of the bar 2 and the respective ear 4. A securing element in the form of a rivet 7, in the present instance, extends through each of the sleeves and the respective ear 4 and the bar 2 and functions to rigidly secure the elements in place and at the same time to permit free rotation of the roller 5.

The spring rule :2: is provided at one of its ends with a loop or formed by turning the end of the spring inward upon itself and being thereafter secured to the body of the spring as shown at W. The loop a is of such proportions as to permit of its passing loosely around the rollers 5, 5 as shown in Fig. 1. By grasping the free or extended portion of the spring :17 and forcing it inward toward the roller 5.from which the spring tangentially projects, the said spring is caused to move around the said rollers 5, 5 and thereby form itself into internally wound layers until completely coiled into the form illustrated in Fig. 3. To project the spring, the above order of operation is reversed. The spring will remain in a quiescent state at any point between the full wound and the fully projected, due to the fact that the outer loop at is maintained constant. I

As shown in Fig. 3, the spring in its compact form comprises two oppositely disposed semi-circular portions y/ and 91 connected by substantially parallel straight portions 3 and y extending between the center lines .2 and a of the arcs defining the semicircular portions 3 and T.-

when the spring rule is in an unrestricted form, it will extend longitudinally into a rod-like state having a cross-sectional form similar to that shown in Fig. 8. When the spring rule is bent, as in the manner effecting its reduction to a compact form the cross-sectional form thereof is changed from the arcuate to a flat and the radius of the curvature of the end portions 3/ and y has been found to naturally assume the arc of the cross-sectional form of the spring in its extended state, corresponding to the radius R as shown in Fi 8. The cross-sectional form of the stralght portions g and {a changes from the flat, at the center lines.

2, a to the arcuate at a point equidistant from and intermediate the said lines a, 2 thus the separate layers of the coil are held against relative lateral movement, one with respect to the others. The spring rule may be readily moved into and out of its compact form by grasping the free end thereof and moving it as above noted, the spring remaining quiescently in the state to which it has been adjusted at or intermediate the two extremes.

In Figs. 4 to 7 inclusive, I have illustrated a form of device adapted to wind the spring in superposed layers, and in the form of a coil having curved ends connected by straight parallel portions and comprises a.

core member 10 having curved end portions 11, 11 whose radii are substantially equal to the'radius R illustrated in Fig. 8, and which are connected by straight parallel side portions 12, 12. One end of the spring may be attached to the core member if desired.

The spring is adapted to wind in superposed layers upon the core member 10, the curved end portions being changed in crosssectional form from the arcuate to the flat and the intermediate straight portions main-.

extending projection 20 which is disposed at a right angle thereto, and extends over the core member 10. The lateral extension 20 acts as a means for retaining the spring in a compact state by arresting any tendency of the said spring to unwind, as clearly shown in Fig. 4:. The core member 10 is provided with a transversely extending member 21 which projects beyond the outside of the said core member in the form of guide flanges 22, 22. A finger grip 23 is provided on the cross-bar 21 intermediate its ends.

To wind the spring on the core member 10, the hand grip 17 is held in one hand and the finger grip 23 is grasped by the other hand. Referring to Fig. 4:, by moving the core member 10 longitudinally to the right until the inner wall of the left curved end of the core member engages the circular face of the pivot member 13, position a, subsequently turning the core member 10 in the direction-of the arrow around the pivot member 13 through position b to position 0 and thereafter repeating the operation until the spring is fully .wound on the core member 10. The lateral projection 20, during the winding operation, engages the free portion of the spring and places the layers of the coil in superposed positions one upon the other. The natural tendency of the spring to extend itself longitudinally functions to keep the layers of the coil in intimate contact with each other.

As in the case of the internally wound coil, the spring at the curved ends of the coil is changed in cross-sectional form from the arcuate to the flat, but retains its arcuate form intermediate the said curved ends.

In Fig. 9, I have illustrated a triangular compact formation which may be either internally or externally wound and in which the rollers 5 5 are substantially of a radius equal to the radius R shown in Fig. 8.

I claim:

1. In combination with a concavo-convex spring having an arcuate cross-sectional form, the curvature of which is set to a 'definite and predetermined radius; means for reducing said spring to a compact formation having longitudinally curved sections alternating with longitudinally straight sections, said means comprising a forming structure against which the spring is laid in superposed layers, said forming structure comprising relatively spaced curved sections the radius of curvature of. each of which is substantially equal to the radius of the crosssectional curvature of the spring.

2. In combination with a concavo-convex spring having an arcuate cross-sectional form, the curvature of which is set to a definite and predetermined radius; means for reducing said spring toa compact format-ion having longitudinally curved sections alternating with longitudinally straight sections, said means comprising a forming structure against which the spring is laid in superposed layers, said forming structure comprising relatively spaced curved sections the radius of curvature of each of which is substantially equal to the radius of the cross-sectional curvature of the spring, said curved sections of the spring as they lie against the curved sections of the forming structure assuming a flat cross-sectional form and said straight sections of the spring intermediate the curved sections of the forming structure maintaining their natural set transverse curvature.

3. In combination with a concavo-convex spring having an arcuate cross-sectional form, the curvature of which is set to a definite and predetermined radius; means for reducing said spring to a compact formation having longitudinally curved sections alternating with longitudinally straight sections, the radius of said curved sections being substantially equal to the natural set radius of the cross-sectional curvature of the spring when in an unrestricted formation, said curved sections assuming a flat crosscoil.

HIRAM A. F ARRAND.

sectional form and said straight sections maintaining their natural set curvature, said reducing means comprising primarily a fixed loop substantially of the shape and proportions of the compact formation into which the spring is to be coiled and against which the spring is laid in superposed layers.

4. In combination with a concavo-convex spring having an arcuate cross-sectional form, the curvature of which is set to a definite and predetermined radius; means for reducing said spring'to a compact formation having longitudinally curved sections alternating with longitudinally straight sections, the radius of said curved sections being substantially equal to the natural set radius of the cross-sectional curvature of the spring when in an unrestricted formation, said curved sections assuming a flat cross-sectional form andsaid straight sections maintaining their natural set curvature, said reducing means comprising primarily a fixed loop substantially of the shape and proportions of the compact formation into which the spring is to be coiled, the subsequent layers of said coil being placed in intimate contact with said fixed loop.

5. In combination with a concavo-convex spring having an arcuate cross-sectional form, the curvature of which is set to a definite and predetermined radius; means for reducing said spring to a compact formation having longitudinally curved sections alternating with longitudinally straight sections, the radius of said curved sections being substantially equal to the natural set radius of the cross-sectional curvature of the spring when in an unrestricted formation, said curved sections assuming a flat cross-sectional form and said straight sec- 

